Patent · US Expired

Digital motor controller

US5350988A · kind A · utility

79Cited by
35References
38Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 2, 1991
Grant dateSep 27, 1994
Priority date
Expiry dateJul 2, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P6/04
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A digital motor controller employs a digital signal processor to generate commutation commands that drive and brake a motor. The commutation commands are pulse width modulated. To avoid shoot-through, the digital signal processor automatically adjusts the widths of the pulses according to the amount of current being drawn by the motor. Motor speed is measured by taking the difference between consecutive samples from a position sensor and dividing the difference by the sampling time. The digital signal processor also closes position, speed and current loops. The commands provided by each loop are limited between upper and lower limits. Further, the digital signal processor automatically adjusts the upper and lower limits to compensate for changes in design characteristics due to variations in temperature. The digital motor controller can be used to control different motors having different design characteristics simply by reprogramming the upper and lower limits. A plurality of digital motor controllers can be used to control motors operating in tandem.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.